Explanation

Reading the question: the prompt presents dubious facts in rapid succession. A natural and healthy impulse is to want to rip the flimsy argument to shreds. However, we don't argue with facts on these questions: what is stated as a fact is a fact. And the question stem is asking us what "must be true," given the prompt. So we should accept the prompt and see what can be inferred from it. We can skip using a filter altogether and go straight to applying the logical test to each answer choice: must it be true? Nothing else matters--including whether the answer choice seems plausible or important.

Logical proof: Testing the logic of each answer choice, we start by finding that (A) need not be true. We are told that mortgage options are helpful to customers, but not that they are most helpful. So (A) is out. Choice (B) is illogical. The converse of a true statement need not be true, and (B) is the converse of a statement in the prompt. Choice (C) looks correct. The prompt tells us, in logical terms, that X->Y->Z. Answer choice (C) says X->Z, which must be true if X->Y->Z. So (C) is in. Choice (D) looks similar to (C) at first, but it introduces a new concept of paying off mortgages on time, and we're not going to be able to establish anything about that concept that "must be true" from the information in the prompt. Choice (E) also contains an out-of-scope element, "restrictions," which we are told nothing about and hence can't draw conclusions about. The correct answer is (C).